const singer = [{
		name: '周杰伦',
		age: 44
	},
	{
		name: '许嵩',
		age: 34
	},
	{
		name: '邓紫棋',
		age: 44
	},
	{
		name: '张碧晨',
		age: 44
	},
	{
		name: '薛之谦',
		age: 44
	},
	{
		name: '封茗囧菌',
		age: 44
	},
]

Array.prototype.my_forEach = function(callback) {
	for (let i = 0; i < this.length; i++) {
		callback(this[i], i, this)
	}
}
singer.my_forEach((item, index, arr) => {
	console.log(item, index, arr);
})
